The North American Species of Pholiota

200. Pholiota innocua sp. nov.

Illustrations. Text figs. 454; 455-457; pl. 89.

Pileus 3-7 cm latus, convexus, demum late convexus, viscidus, subfulvus vel fulvus, ad marginem laete luteus. Contextus luteus. Lamellae laete luteae confertae, latae, demum subdecurrentes. Stipes 4-6 cm longus, 9-12 mm crassus, solidus, pallide luteus, sursum pruinosus, deorsum de mum fulvus. Velum subfulvum, fibrillosum. Sporae 4.4-6.5 x 2.8-3.5 µ. Pleurocystidia utriformia 30-46 (60) x 10-15 µ. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Warrensburg, New York, 12 Sept. 1934. Smith 798.

Pileus 3-7 cm broad, convex with a bent in margin which remains decurved a long time, nearly plane or more rarely slightly depressed in age but some slightly umbonate, margin at first appressed fibrillose from patches of tawny fibrils, surface covered by a thin gelatinous layer; color "tawny" (tawny) on disc and pale lemon-yellow ("pinnard-yellow" to "baryta-yellow") over marginal area. Context watery firm, yellowish, odor and taste not distinctive, FeSO4 slowly green on dried pileus cutis, finally inky black.

Lamellae pale yellow ("Baryta-yellow"), close, moderately broad, equal, adnate to decurrent (not at all sinuate or adnexed), edges even.

Stipe 4-6 cm long, 9-12 mm equal or nearly so, solid pale yellow above ("pale chalchedony-yellow") and pruinose to fibrillose-pruinose, below dull yellow but soon rusty stained, base with matted yellowish mycelium as dried.

Spores 4.5-6 (6.5) x 2.8-3.5 µ, smooth, apical pore not distinct; shape in face view oblong, slightly bean-shaped in profile; yellow in KOH, in Melzer's sol. merely pale cinnamon brown; wall slightly thickened (-0.25 µ).

Basidia 4-spored, 18-22 x 5-6 µ, hyaline in KOH, yellowish in Melzer's. Pleurocystidia abundant and projecting, 30-46 (60) x 10-15 µ, utriform (broadly fusoid-ventricose with rounded apex), when first revived in KOH with reddish to rusty ochraceous content but clearing on standing, finally hyaline, in Melzer's yellowish to hyaline or retaining some brown debris, walls thin to rarely slightly thickened (± 0.5 µ) and either smooth or with some debris adhering, as revived often with rod-like bodies and particles in neck. Cheilocystidia smaller than pleurocystidia (26-35 x 10-16 µ) and many varying in shape to clavate to nearly vesiculose-pedicellate, becoming hyaline in KOH and with no distinct reaction in Melzer's reagent the walls frequently thickened and yellow in KOH. Caulocystidia not characteristic, a few clavate hyphal ends present above the veil line.

Gill trama in KOH of ochraceous to pale tawny parallel hyphae with non-gelatinous walls which in Melzer's reagent are dull pale rusty brown; subhymenium of narrow interwoven much-branched hyphae only obscurely gelatinous in KOH. Pileus cutis a pellicle of appressed narrow (2-3 µ) hyphae yellow to tawny as revived in KOH, the hyphal walls smooth to minutely incrusted by bands or spirals and the walls not obviously gelatinous though the hyphae are imbedded in a gelatinous matrix; beneath this the context hyphae 4-11 µ diam., loosely interwoven and non-gelatinous. No hypodermium evident. Clamp connections readily observed at nearly all septa.

Habit, Habitat, and Distribution: Caespitose gregarious around beech logs and debris but not on the wood, Warrensburg, New York, Sept. 12, 1934. Smith 798, type.

Observations: This species by virtue of small spores and broadly rounded pleurocystidia appears to be closely related to P. polychroa but is readily distinct by the rusty to yellow pilei. Its distinctive features in addition to those relating it to P. polychroa are the typically convex to depressed pileus, caespitose-gregarious fruiting pattern and moderately thin veil. We did not find any thick-walled pleurocystidia in any of the mounts we made, but the presence of so many thick-walled cheilocystidia causes one to speculate as to whether the same feature will not be found eventually in the pleurocystidia of some collections of this species.